1. Field of the Invention
The present invention relates to a static semiconductor storage element, and more particularly to such an element including a pair of complementary field effect transistors.
2. The Prior Art
Many designs for semiconductor storage devices have been developed, including static and dynamic types. One previous static type is disclosed and described in copending U.S. application Ser. No. 457,223, filed Apr. 2, 1974. That application describes a storage element made up of five transistors. Although this design is satisfactory as far as its operation is concerned, the requirement of five transistors, and the various interconnections which are required in order to form an operative circuit, take up a relatively large amount of space.
Static storage devices are preferably formed on a single wafer or "chip" of silicon or other semiconducting or insulating material. This mode of construction greatly reduces the required amount of space, as compared with the use of discrete circuit elements, but the requirement of five transistors in the circuit demands a relatively large area of the substrate for each individual storage element. It is desirable to reduce, as much as possible, the amount of substrate area required for each storage element so as to pack as many storage elements as possible into a single integrated circuit, and it is therefore desirable to design a circuit which requires fewer transistors and fewer and simpler connections among the components.